Paper Title
Effect of Core Type and Size on Mechanical Properties of Composite Friction Spun Yarns

Abstract
Composite yarns consist of two distinct components, i.e., core and sheath. Different types and combinations of core and sheath are used to make composite yarns with varying properties. In this paper the focus is on selected parameters that influence the mechanical properties of DREF 3 composite yarns. Core material and yarn linear density were changed to make 18 different types of composite yarns having linear densities 118, 98 and 84 tex. Two types of core materials stainless steel (S.S) and E-glass were used having linear densities 11, 17 (0.4 & 0.5 micron) and 5.5, 11, 17, 33 tex respectively. Sheath material was Kevlar®29 in all the yarns. The sheath portion was kept between 95% and 60%. The performance test selected for these yarns was tensile strength. Mechanical tests of the yarns were statistically analyzed and the analysis showed a significant effect of core type and core-sheath ratio on tensile properties of composite yarns. Tensile strength of the composite yarns significantly improved in the glass core yarns while Elongation at break was better for steel core yarns. Key Words - DREF 3 Composite yarns, Friction Spun yarns, Mechanical Properties, Elongation at break, Time to break